Method and machine for forming metal



Nov. 15 W49 c. E. UNGER METHOD AND MACHINE FOR FORMING METAL 2Sheets-Sheet 1 Filed Aug. 10, 1944 INVENTOR.

CHESTER E. UNGER Nov. 15, 1949 c. E. UNGER METHOD AND MACHINE FORFORMING METAL 2 Sheets-Sheet 2 Filed Aug. 10, 1344 F I G 5 INVENTOR.

CHESTER E.UNGER BY Mmm Patented Nov. 15, 1949 METHOD AND MACHINE FORFORMING METAL Chester E. Unger, Mishawaka, Ind., assignor to AmericanWheelabrator & Equipment Corporation, a corporation of DelawareApplication August 10, 1944, Serial No. 548,919

9 Claims.

This invention relates to a method and machine for forming metal, moreparticularly to a method and machine for making metal shot.

The invention provides a method and machine for producing metal shot,such as for example steel shot, in a continuous operation from a streamof molten metal.

According to the invention a stream of molten metal is directed onto asurface while the surface is being imparted a compound movementconsisting of a rapid vibratory movement in a direction substantiallynormal to the surface element impacted by the stream of metal and atranslatory movement substantially at right angles to the direction ofthe vibratory movement. The stream of metal directed onto the vibratingsurface is broken up into individual particles and the particles aredischarged from the surface in a predetermined direction. Subsequentlythe particles are cooled below their solidification point and collected.

The vibrating surface may be made of a refractory material to which themetal will not adhere. It may also be made of metal, means beingprovided for producing a protective film on the metal surface to preventthe molten metal from adhering. According to a feature of this inventiona protective film is formed by a layer of rapidly moving air, the airfilm being created at the periphery of a rapidly spinning wheel.

The invention further provides machines for the continuous production ofmetal shot according to my method.

The various objects, features and advantages of this invention willappear more fully from the detailed description which followsaccompanied by drawings illustrating my method and showing preferredforms of machines for carrying it out.

The invention also consists in certain new and original features ofconstruction in combination of parts hereinafter set forth and claimed.

Although the novel features which are believed to be characteristic ofthis invention will be particularly pointed out in the claims appendedhereto, the invention itself, its objects and advantages, and the mannerin which it may be carried out may be better understood by referring tothe following detailed description taken in connection with theaccompanying drawings forming a part of it in which- Fig. 1 is a diagramillustrating the method of continuously producing metal shot;

Fig. 2 is a side elevation, partly in section, of a machine for thecontinuous production of cast metal shot;

Fig. 3 is a perspective view of a vibrating member which may be used inthe machine shown in Fig. 2;

Fig. 4 is an elevational side view, partly in section, of a vibratingwheel for making metal shot; and

Fig. 5 is an end view of the machine shown in Fig. 4, a section beingtaken on line 5-5.

In the following description and in the claims various details will beidentified by specific names for convenience. These names, however, areintended to be as generic in their application as the art will permit.Like reference characters refer to like parts in the several figures ofthe drawings.

In the drawings accompanying, and forming part of this descriptioncertain specific disclosure of the invention is made for the purpose ofexplanation, but it is understood that details may be modified invarious respects without departure from the broad aspects of theinvention.

The principle of the invention is diagrammatically illustrated inFig. 1. A stream of molten metal I is directed from a pouring spout 2onto a small surface element 3 which in actual practice forms a part ofa larger surface. The surface element may be inclined by an angleappearing in the diagram between a vertical line 4 and an axis 5 normalto the surface element. A rapid vibratory motion substantially in thedirection of axis 5 is imparted to the surface element as indicated byan arrow 6. A further and translatory movement is imparted to thesurface element 3 in a direction substantially parallel to the surfaceelement. This translatory movement may be combined with the vibratorymovement and may either be of oscillatory or continuous character. Thedirection of the translatory movement is indicated by an arrow 1. Thetranslatory movement may, as will later be shown, be produced bycontinuous rotation of the surface element in one direction or it may beproduced as a component of a compound movement such as for example asubstantially orbiculate motion of the surface element indicated by aseries of arrows 8, 8' and 9, 9'. The arrows 8 and 8' represent thetranslatory component, and arrows 9 and 9' the normal component of themovement.

The stream of metal I is broken up at the surface element 3 intoindividual particles which are thrown off and cooled below theirsolidification point, for example by letting them drop into a bath ofcooling liquid l0.

Referring now to Fig. 2 showing a machine for practicing the illustratedmethod, a base ll carries a crosshead l2 movable about a pivot l3. A

rod I4 is slidable in a bore l5 of the crosshead l2 and is mounted withits ends [6 and I1 in lugs l8 and IQ of a head 28.

The head forms a hollow chamber 2| accommodating a dispersing member 22which protrudes through an aperture 23 at the top of the chamber;

Cooling liquid may be circulated in the chamber 21 and enters through aflexible tube 24 at a port 25 and is withdrawn through a flexible tube26 leading from a port 21.

The dispersing member 22 may be made of a ceramic material capable, .ofwithstanding the high temperatures of molten metal and possessingsufficient strength to stand up under vibrafeed mechanism.

-rmember outwardly so as to maintain the distance 11 between the topsurface of the dispersing member and. the pouring spout 2 substantiallycontions. Graphite has been found satisfactory as material for thedispersing member.

The dispersing member is mounted on .a stem 28 provided with a collar 29supporting the lower end surface of the dispersing member. The stemextends througha threaded aperture 30 in a boss '3l at the "bottom ofthechamber. Cooling liquid is. prevented from escaping past the stem 28byxa packing 3.I" in a hollow portion 32 at the bottom of the head '28,the packing being compressed by a. threaded packing collar 33.

ThestemIZB is provided with a threaded end 34 screwed in a threadedsleeve 35 .in an outer member. 36 of an eccentric. The outer member 36.supports the. head 20 by rods 31 and 38.

.An' eccentric disk .39 is .mounted on a drive shaft 48 connected" to "asuitable source of .motive power (not shown).

A worm gear 41 is mounted on the drive shaft '40 and meshes with awormwheel 42 on .an intermediary shaft 43'. The intermediar shaft .43 alsocarries a worm gear 44 meshing with a further worm wheel '45 on avertical shaft 46.

"The vertical shaft "46 drives a feed shaft 41 through bevel gears 48and Y49 on shafts 46. and 41, respectively.

The feed shaft 41 carries. an eccentric disk 50 engaging an outer member5| to whicha connecting rod'52 is 'hingedly connected at 53. Theconnecting rod 52 carries a fork piyotally engaginga ratchetisupport 55at 5.6. The ratchet support is rotatable mounted on a flange 51 of thesleeve 35.:and carriesa pawl 58, pivoted at 59. The pawl engages aratchet wheel 6.8,- provided with..a key .6l. engaging a keyway 62 inthe stem 28 so as to rotate the stem.

The operation of the-machine is as follows:

The drive shaft 48. is. driven at a rapid rate. The eccentric, 3.9., 36imparts tothe-head 20 and the dispersing. member 22 a vibratory movementwhose. chief component. is anoscil ation in. the direction. of the axis.of the stem 28. In addition the. head 20 and the. dispersing -member.22per- .forman oscillating movementabout thepivot 13. The oscillatorymovement .in theidirectionof the .axisof the stem. 28. causestherod M ofthe head to. slide back and .forthin the bore 1.5 of the crosshead. andthe oscillatory. movement about the. pivot. l3..causes the headto tiltaboutthe pivot l3. Cooling ..liquidmay be circulated through the chamber.2Lof. the head 28- through conduitsldandlfi- A stream.of molten-:-metalis discharged from thespout Zontothetopsurface ofthe dispersing member22. and-isrbroken .up into individual particles 63 which are thrown offby-the dispersing member in a predetermined direction "I -0' compensatefor wear of the .top surface of the -r'dispersinga-member .22; themember is progressively rotated and also fed outwardly by the stant. 7

It has been found advantageous to incline i the: axis. of'thastem. 28approximately fifteen degrees. with respect to the vertical in order todirect the discharge of the molten metal particles. This is a particularfeature of the machine permitting a trough of coolingliquid tobeso-placed with respect to; the' machine that all the'discharged metalparticles dropinto it without spillage.

Steel shot of the commercial sizes of between Nos. 15 and 40 havebeenproduced with this machine. The size of the'shotmay be controlled byadjusting the rate o'f-the drive shaft 40'. A rate of between-"3500 'and"4000B. '1. M. has been found to give excellent results. Uniformspherical shot predominantly of 'size'No; 20 has been produced by themachine operated at a'rate of 3800 R. P. M. of the drive shaft 48, steelof a temperature of 3000 Fahrenheit being discharged onto the dispersing-member at the rate of 50 pounds per minute. The stroke of the cam 39 inthis instance was 'onequarter of one inch. I

A modified form of dispersing member is-shown in Fig. 3. The dispersingmember 20' comprises a hollow steel plate '83 mounted on a non-rotatablestem 28. Cooling liquid is circulated through the hollow interior of theplate 63 through ducts '24 and 26. Anorifice 64 discharges a burning jetof acetylene gas which is directed onto the top surface of the hollowsteel plate 63 and deposits a protective layer or film of carbon thereonto prevent the molten metal from adhering to thesteel surface.

The operation of the device shown in Fig. 3 corresponds in all detailsto the operation of. the machine shown in Fig. 2 with the exception thatno continuous feeding of thedispersing member towards the pouring. spout2. is required since the dispersing steel plate is..not subject to.appreciable wear.

A modified. form of machine. for. the continuous production of metal.shot is shown in Fig. 4. The machine comprises a bell shaped wheel..65having a smooth peripheral dispersing .surface 65. The wheel is mountedon a. substantially horizontal drive shaft 61.resting in bearings 68 and69. The bearings have base plates 10 and 1i to which are vulcanized.blocks 12 .and 13 of rubber or other resilient...material. The.resilient blocks 12 and -13,-in. turn, are vulcanized to mounting plates14 and. 15. secured .to abase- 1.6 by bolts 1.1. 7

One end ofthe. drive shaft. 61. carries. adrive pulley E8 and the otherend of the shaft engages the upper bearin .18 .of aconnecting. rod 80.-

The lower end-of the connecting. rodlifl forms the outer member .8 I.ofan: eccentric. An eccentric disk 82 runsin the. outermemberfil. and isfixedly mounted on a shaft 83 supporteddn bearings 84 and 85 secured tothe underside of the base 16 by bolts 86. A drive pulley 81 is securedto one end of the drive shaft 83 for the eccentric.

A cooling fan 88 is mounted on the drive shaft for the wheel within thehollow bell-shaped space of the wheel. The fan acts in the manner of acentrifugal fan causing a fiow of air into the interior of the bellshaped wheel space along the drive shaft 61 and a discharge of air alongthe inner periphery of the wheel thus cooling the rim of the wheel. Awiper 89 may be mounted adjacent the periphery of the wheel.

The operation of the device is as follows:

The drive pulleys 18 and 8'! are preferably connected to different primemovers provided with means for controlling their speeds. The shaft 61 isdriven at a rapid rate, preferably of the order of 3000 to 4000 R. P. M.The shaft 83 is driven causing a rapid. vibratory motion to be impartedto the wheel 65 through the eccentric 8|, B2 and the connecting rod 80.The rubber blocks 12 and 13 in the supports of the bearing 68 and 69permit of sufiicient deflection of the axis of the shaft 61 from thehorizontal to execute the vibratory movements forced upon the wheel 65by the eccentric.

A stream I of molten metal is discharged onto the periphery 66 of thewheel from a spout 2 and is dispersed into individual particles '63which are discharged in a predetermined direction to be cooled andsolidified.

The rapid rotation of the wheel causes a film of air to be dragged alonthe periphery of the Wheel. This film of air is found to act as aprotective layer preventing the molten metal from adhering to the metalrim of the wheel.

Highly satisfactory results are obtained with a wheel having a diameterof 12 inches driven at a rate of 3600 R. P. M. and vibrated between 1000and 3600 cycles per minute. Molten steel SAE 1030 discharged at the rateof 50 pounds per minute onto the wheel surface was formed into perfectsolid round steel shot of the commercial sizes between and 40. Due tothe effective cooling provided by the fan 88 no appreciable increase inheat of the periphery of the wheel was observed during the operation.

Obviously the present invention is not restricted to the use of thespecific machines herein shown and described. Various changes andsubstitutions may be made, for example the protective film of air formedaround the periphery of the wheel may be replaced by a film of othermatter such as carbon as hereinbefore described. A film of water may beapplied to the periphery of the wheel either by spraying water on thewheel or by immersin the lowermost portion of the wheel in a bath ofwater causing enough water to be dragged along by the wheel to form aprotective surface on it. The air cooling of the wheel may be replacedby water cooling. Also various features may be added or omitted,equivalent devices and features may be substituted, dimensions andspeeds may be correspondingly changed and various other changes be made.All such modifications will be apparent to a person skilled in the artand manifestly do not involve a departure from the spirit and teachingsof this invention.

What is claimed is:

l. The method of making metal shot which comprises, directing acontinuous flow of molten metal onto an imperforate surface;simultaneously imparting to said surface a definite and 6,, controlledvibratory motion in a direction substantially normal to the extent ofthe surface element impacted by said flow and a movement in a directionsubstantially parallel to said surface element, the vibration beingsufiiciently rapid to disperse said flow of metal into individualparticles by rebound from said surface; and cooling said particles belowtheir solidification point.

2. The method of making metal shot which comprises, imparting to animperforate surface a translatory movement substantially in thedirection in which said surface extends and a controlled and definitevibratory motion in a direction substantially normal to said surface;directing a continuous flow of molten metal onto said surface, thevibratory motion of said surface being sufiiciently rapid to cause saidflow of metal to be broken up into individual particles by rebound fromsaid surface; and cooling said par-.- ticles below their solidificationpoint.

3. The method of making metal shot which comprises, directing a flow ofmolten metal onto the periphery of a wheel spinning about asubstantially horizontal axis, imparting to the wheel simultaneously acontrolled and definite vibration in a direction at right angles to thespin axis and substantially normal to the surface area of the peripheryimpacted by the fiow of metal, the vibration being sufficiently rapid tocause the flow of metal to be broken up into individual particles byrebound from said periphery; and cooling said particles below theirsolidification point.

4. The method of making metal shot which comprises, directing a flow ofmolten metal onto the substantially smooth periphery of a Wheel having asubstantially horizontal axis; simultaneously imparting to the wheel acontrolled and definite vibration in a direction substantially normal tothe surface area of the periphery impacted by the fiow simultaneouslyspinning said wheel about said axis, thereby causing a film of air to bedragged along by said periphery, the rate of spin being suificientlyhigh to set up a film of air dense enough to prevent said flow of metalfrom penetrating said film and adhering to said periphery, the vibrationbeing sufficiently rapid to cause said fiow to be broken up by reboundinto individual particles; and cooling said particles below thesolidification point.

5. The method of making metal shot which comprises, directing acontinuous flow of molten metal onto an imperforate dispersing surface;simultaneously imparting a definite and controlled compound vibratorymotion to said surface having a translatory component substantially inthe direction of the surface impacted by said flow and a vibratorycomponent substantially normal to said surface, the vibratory motionbeing sufiiciently rapid to cause said flow to be broken up intoindividual particles by rebound from said surface; and cooling saidparticles below the solidification point.

6. The method of making metal shot which comprises, directing acontinuous flow of molten metal onto a solid dispersing surface;simultaneously imparting a controlled and definite compound vibratorymotion to said surface having a translatory component substantially inthe direction of the surface impacted by said flow and a vibratorycomponent substantially normal to said surface, the vibratory motionbeing sufiiciently rapid to cause said flow to be broken up intoindividual particles by rebound from said '1' surface; maintaining:aninsulatingi film: on said surface to-preventthe molten: metal from.adhering, to. said: surface; andv cooling said particles below; thesolidification point.

7. A machine for the continuous production of metal shot .comprising, incombination, a wheel; means;- for-:spinning-said:whee1 about-asubstantially horizontal axis; means for directing a stream zof moltenmetal. against the rim of said wheel; and means for vibrating said wheelin a substantially vertical direction.

8.; A machine; for the-continuous production of metal shot comprising,in combination, a wheel; means for spinning said wheel about asubstantially: horizontal axis; means for directing; a stream.ofxmoltencmetal against the rim of said wheel;v andmeans :for'vibrating said wheel v in a direction substantially normal to the areaof the rimiimpactedbythe stream of the molten metal.

9. A machine for the continuous production of metal shot comprising, awheel; a substantially horizontal shaftsupporting said wheel; abearing-resiliently supporting said shaft near one end;

8; a iree bearingon said-shaft near theother, end; and an eccentricengaging said free bearing to .impart a vibratory motion to said shaft;and means fordirecting a stream of molten metal against the rim of saidwheel.

CHESTER E. UNGER.

REFERENCES. CITED The following references are of record in the file ofthis patent:

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